Best Practices for License enforcement

We have been building a wordpress plugin addressing a specific need. We will have a functional base version (free) and a paid version that will have added features. Are there any best practice in how to enforce licensing on the paid version ? I ask this since once the paid version is downloaded, one could modify the source code easily and circumvent any licensing (because unlike binary exe, it’s all just php/js). While this may not be fully avoidable, if anyone has any guidance to share, I would greatly appreciate it. Specifically, what’s the best that could be done without causing any customer friction.

If you’re concerned, talk to a lawyer. 🙂 No one on here can give you any sort of advice on copyright, legal, etc issues.

Now, I’m not a lawyer, but the good plugins that I’ve seen before that use the free/pro model do a few things, and none of that actually restricts copying. Remember that due to the licensing of WordPress as GPL, anything written fo rit (themes, plugins) all need to follow the GPL license, which allows code copying and re-use. The way that most places get around that is that they offer pro updates only to people that have purchased the plugin from them. There’s a few e-commerce plugins that can either do this out-of-the-box or with an extension or two.

That depends 100% of what you use to sell the plugins with. There’s nothing built into the WordPress system by default that does that, mainly becuase everything is geared towards plugins from the WordPress site, which are all free.